The present invention relates generally to tactile generators, and particularly to tactile generators in wireless communications devices.
Tactile generators produce vibration by rotating an unbalanced load with a motor. The amount of vibration produced in a given tactile generator is a function of the mass of the unbalanced load, the distance of the center of mass of the load from a rotational axis, and the speed at which it rotates. In conventional devices, these parameters are often fixed by the manufacturer and cannot be changed. As a result, the amount of vibration that can be imparted by conventional devices is also fixed.
Further, in conventional devices, the center of mass of the load resides at a fixed distance from the rotational axis, and as such, typically requires a fixed amount of current to start the load rotating. This starting current is substantially greater than the corresponding operating current for a given motor design. However, a device that is unable to draw the requisite amount of starting current will be unable to rotate the load to produce vibration. Accordingly, what is needed is a device that can produce varying amounts of vibration and is capable of operating on reduced starting current loads.